Bomb tail construction



BOMB TAIL CONSTRUCTION Filed Dec. 11, 1953 [77 1 527 [SF Caveat-14 86167;; ya/v United States Patent BOMB TAIL CONSTRUCTION George Albert Lyon, Detroit,Mich. Application December 11, 1953, Serial No. 397,643

1 Claim. (Cl. 102-2) The present invention relates to improvements in aerial bombs for military use and more particularly relates to streamlined bombs of the low drag type.

Heretofore in bomb construction it has been customary to produce the various tubular portions of the bomb from a plurality of assembled parts, or from fiat material bent into tubular shape and butt-welded along the meeting edges. Especially in the tail structure, including the guide fins has presented considerable problem in construction, usually consisting of a plurality of fin members attached to a tail piece or to fin spars assembled in the desired tail formation.

An important object of the present invention is to effect substantial reduction in the number of individual parts going into the structure at the tail end portion of an airplane-type aerial bomb.

Another object of the invention is to provide a tail fin and spar structure of improved construction.

A further object of the invention is to provide an improved method of making a combined tail fin and spar structure for aerial bombs from a single piece of material.

Still another object of the invention is to provide an improved rear end assembly for aerial bombs.

It is another object of the invention to provide an improved method of making a rear end assembly for aerial bombs.

Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of -a preferred embodiment thereof, taken in conjunction with the accompanying drawings, in which:

Figure 1 is a small scale, more or less schematic illustration of a low drag aerial bomb embodying features of the present invention;

Figure 2 is a larger scale fragmentary side elevational View, partially in section, showing the cone skin or rear chamber portion of the bomb and the tail section of the bomb before formation of the tail section into fin and spar form;

Figure 3 is a rear end view of the tail member of Figure 2; and

Figure 4 is a rear end view of the tail member following collapsing and shaping thereof into fin and spar form.

A low drag bomb, as shown in Fig. l, embodying the present invention comprises a bomb head shown in phantom outline in Fig. l, to which is attached a rear chamber or cone skin portion 5 carrying a finned tail portion 7. The entire assembly is of generally cigar-shape, streamlined elongated construction to afford minimum wind resistance when launched from a high speed bombing plane.

In a preferred construction, the rear chamber or cone skin portion 5 comprises a generally conically, truncated shell which is adapted to be drawn in one piece from suitable rolled metal slab such as steel of appropriate grade and gauge. At its forward, wider mouth portion, the member 5 is provided with an internally thickened 2,873,674 Patented Feb. 17, 1959 ice . annular shoulder collar portion Swhich may be threaded member 5 it tapers toward a rear end or base wall 9 which may provide a bulkhead or partition, or part of such a bulkhead or partition between the member 5 and the tail section or structure 7. 1

According to the present invention, the tail structure 7 is also, at least primarily, constructed from a single piece of material such as suitable grade and gauge steel, finally shaped to provide a rearwardly tapered tail spar portion 10 and a uniform series of tail fins 11 which project radially to a sufficient extent beyond the main diameter of the bomb to serve effectively in guiding the bomb head-on in flight.

In making the tail section 7, the metal blank from which it is fabricated is first shaped by any suitable method such as press-drawing into substantially frusto-conical shape'substantially as shown in Figs. 2 and 3 to provide a flaring rearwardly opening side wall and a forward smaller diameter end wall 12. In a preferred form, the end wall 12 may be of substantially the same diameter as the cone skin end wall 9 and disposed in face to face concentric abutment therewith and welded or otherwise secured thereto whereby to cooperate in providing a double thickness bulkhead or partition. It will be under stood, of course, that the end walls 9 and 12, may be secured together while the tail member is still in the generally bell shape shown in Figs. 2 and 3 or assembly may be effected following final shaping of the tail member.

From the generally bell shape, the tail member 7 is symmetrically contracted along longitudinal lines into generally starshape cross-section as shown in dash out line in Figs. 3 and 4. The points of the star formation provide the vanes 11, with the points of the star provided by longitudinally extending ribs having their rear extremities drawn in only a short distance from the original rear end perimeter as occasioned by necessary contraction resulting from the substantially inwardly pressed portions of the member intermediate the fin ribs. In completing the fin formation, the portions intermediate the fin ribs are contracted toward one another until the rear end extremity portions thereof are in close proximity concentrically about the axis of the member and defining therebetween a diameter which is only a fraction as great as the front end diameter of the tail member. Moreover, during the final contraction, the material between the fin ribs is fashioned to provide generally lance-head shaped, outwardly convex, complementary segmental reinforcing and bracing panels providing the struts 10. The relationship of the struts 10 and the sides of the fin ribs 11 is such as to maintain the collapsed fin rib side walls substantially against spreading apart. This result is attained substantially by virtue of the rigid structure of the strut panel portions 10 and the rigid manner in which they extend from the base wall 12. As will be noted on comparison of Figures 1 and 4, the panels 10 are of greatest width at their junctures with the base wall 12 and are substantially rigidified by being on a peripheral curve at their juncture with the base wall while the panels 10 converge toward the rear end of the tail construction. By preference the external shape of the struts is complementary to the external taper of and coactive in general continuation of the longitudinal taper line of the cone skin member 5, as best seen in Fig. 1. In the completed tail fin member 7, the rear extremities of the fins may be closed off or may be left open as desired.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

Iclaimas my invention:

In a bomb structure; a' cone skin shell member of substantially cup shape havinga-rear wall and aside tubularwall projecting forwardly therefrom on a symmetrical taper and having forward end means for attachment to a body:shell, and a generally cupfshaped tail fin member comprising a one-piece-sheet metal structure having aforwardclbasewall attached concentrically to said cone skin shell'base wall, said tail'fin member having an elongatedrearwardly projecting sidewall collapsed toward the axis-.of'the tail'member and providing radial fins-projecting. substantially beyond'the diameter of saidtail-fin member end wall and converging thereto, with generally lance-shaped segmental-intermediate strut portions converging-1 rearwardly from-the diameter ofsaid end wall and maintaining the. fins; against spreading open, saidsegmental strut portions conforming symmetrically to the taper of the-coneskin shell to effect a streamlined relationship toward a point of convergence beyond the rear end of the assembly.

References Cited in the file of this patent V UNITED STATES PATENTS 1,189,382 Peck July 4, 1916 1,298,222 Kane Mar. 25, 1919 1,515,705 Short Nov. 18, 1924 2,070,946 Joyce Feb. 16, 1937 FOREIGN PATENTS 1,008,613 France Feb. 27, 1952 

